Two question, Rivets and Drain Hole/Plug

I just bought a late 70s era 12' flat bottom.

I leak checked it last night (filled it with water on saw horses) and I found three slow rivet leaks and the drain hole leaked fast (yes I had the plug in).

Here are the questions.

1. Is there something better for me to use than drilling out the rivets and replacing them or should I stick to a marine rivet and just replace the three?
2. Do I need a drain hole, it seems to be bent up a bit which is causing the plug not to seal. Should I permanently seal it, or is it better to keep it?

I appreciate any answers.

For the rivets, before drilling out and replacing, try this... put something heavy, like the end of a sledge hammer on one side, and then have some one tap it on the other side with a lighter sledge or a hammer. Many times this will tighten them back up and solve your problem.

As far as your drain plug... It's good to have if you leave your boat in the weather exposed to rain. This will allow the boat to drain while it's "by itself". If you cover it and no water seeps in you can plug the hole, but you're going to need a bilge pump in the back to get rid of excess water you may get in the boat - my boat will fill up fast if I'm out fishing while it's raining.

Buck the rivets like russ explained and if it still leaks, you could seal them with a bit of silicon. As far as the drain plug, you need to keep it. Check the plug to make sure the rubber is in good condition . They also can be adjusted by tightening them up so they expand more before you put them in.

i agree buck the rivets